Sharp CX48K4 Service Manual page 9

Chassis no. ua-1
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HORIZONTAL AND VERTICAL DEFLECTION LOOP ADJUSTMENT
NO. Adjustment part
Adjusting procedure and conditions
1
V-LINEARITY
1. Receive Monoscope Pattern Signal.
(I
2
C BUS
2. Call the "V-LIN" mode.
CONTROL)
3. Increase or decrease "V-LIN" by Volume key till
the horizontal line in the center of monoscope is
just at the position where the blanking starts.
2
V-CENTER
1. Call the "V-CENT" mode.
(I
2
C BUS
2. Increase or decrease "V-CENT" by Volume key
CONTROL)
till the picture is centered.
3
V - AMP
1. Call the "V-AMP" mode.
(I
2
C BUS
2. Increase or decrease "V- AMP" by Volume key
CONTROL)
to set overscan of 9.5% typical.
Adjustment Spec 9.5% range +1% -0%.
4
S-CORREC-
FIXED DATA, NO NEED TO ADJUST.
TION
(I
2
C
BUS CON-
TROL)
5
H - CENTER
1. Call the "H-CENT" mode.
2. Increase or decrease "H-CENT" by Volume key
to center the picture horizontal.
6
SUB-
1. Call the "SUB-SHP" mode.
SHARPNESS
2. Set "SUB-SHP" to 20 by pressing Volume down
key.
7
Focus
1. Receive the "Monoscope Pattern" signal.
adjustment
2. Press R/C to set Picture NORMAL condition.
3. Adjust the focus control to get the best focus.
PAL CHROMA ADJUSTMENT
NO. Adjustment part
Adjusting procedure and conditions
1
SUB COLOUR
1. Receive the "PAL Colour Bar" signal.
(I
2
C BUS
2. Press R/C to set Picture Normal condition.
CONTROL)
3. Connect the oscilloscope to Red cathode
(C881 and R885).
» Range
: 20 V/div. (AC) (Use 10:1 probe)
» Sweep time : 10 µsec/div.
4. Using the R/C call "SUB COL" in SERVICE
mode. Adjust SUB COLOUR bus data, so that
the 75% White & Red portions of PAL Colour
Bar be at the same level shown as Fig. 8.
5. Clear the SERVICE mode.
Waveform and others
Waveform and others
Cy G
W Y 100%W
Mg R
75%
Fig. 8
9-1
NTSC CHROMA ADJUSTMENT
NO. Adjustment part
Adjusting procedure and conditions
1
SUB-TINT
1. Receive the "NTSC3.58 Colour Bar" signal
(I
2
C BUS
through AV in.
CONTROL)
2. Connect the oscilloscope to TP853 (Pin (5) of
P882) BLUE-OUT.
» Range
» Sweep time : 10 µsec/div.
3. Call the "SUB-TINT" mode in service mode.
Adjust the "SUB-TINT" bus data to obtain the
waveform shown as Fig. 9.
4. Clear the SERVICE mode.
PROTECTOR OPERATION CHECKING
NO. Adjustment part
Adjusting procedure and conditions
1
BEAM
1. Receive "Monoscope Pattern" signal.
PROTECTOR
2. Set CONTRAST MAX.
3. Set BRIGHT MAX.
4. During the Collector & Emitter of Q883/5/7
short, make sure the protector ON and switch
to standby mode.
2
H, V
1. Receive "Monoscope Pattern" signal.
PROTECTOR
2. Connect output of Bias Box to D607 cathode
(R606 side).
3. Set voltage of Bias Box to 18V and make sure
the protector is not work.
4. Set voltage of Bias Box to 27V, and make sure
the protector is work.
3
Other
1. Once finish rectified Electrolytic Capacitor short
protectors
testing in +B line, check all possible damaged
components on +B line.
(Use random selected set for inspection)
A/V INPUT AND OUTPUT CHECKING
B
NO. Adjustment part
Adjusting procedure and conditions
1
VIDEO AND
1. Receive the "PAL Colour Bar" signal (100%
AUDIO OUT-
White Color Bar, Sound 400 Hz 100% Mod.)
PUT CHECK
2. Terminate the Video output with a 75 ohm im-
pedance. Make sure the output is as specified
(1.0 Vp-p ±3 dB).
3. Terminate the Audio output with a 10k ohm im-
pedance. Make sure the output is as specified
(1.76 Vp-p ±3 dB).
2
VIDEO AND
1. Using the TV/AV key on the remote controller,
AUDIO INPUT
make sure that the modes change in order of
CHECK
TV, AV1, AV2 & TV again and the video & audio
output are according to the input terminal for
each mode.
Waveform and others
SAME LEVEL
: 100mV/div. (AC)(Use Probe 10:1)
W
Y Cy G Mg R B
Fig. 9
Waveform and others
* Select one of Q883/5/7 to do
each short test.
Waveform and others
9-2

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